Conventionally, there is an illumination apparatus having a flexible substrate including a front surface and a rear surface on the opposite side of the front surface. The substrate has multiple LEDs (Light Emitting Diodes) mounted on a wiring pattern formed on the front surface and multiple heat radiation plates mounted on the rear surface.
The multiple heat radiation plates are adhered to the substrate to cover parts of the substrate corresponding to areas on which the LEDs are mounted. The heat radiation plates may be adhered to the substrate with an adhesive agent.
As described in, for example, Japanese Laid-Open Patent Publication No. 2003-092011, the conventional illumination apparatus has a LED mounted on a wiring substrate including a substrate, a wiring pattern (wiring), and a heat radiation plate.
In the wiring substrate of the conventional illumination apparatus, the wiring and the heat radiation plate are connected by way of a substrate that is formed of a resin material (e.g., fiberglass reinforced plastic) having a low thermal conductivity.
Therefore, the wiring substrate of the conventional illumination apparatus is unable to efficiently transfer heat generated by an electronic component having a heat generating property (e.g., LED) from the wiring on the front surface of the substrate to the heat radiation plate on the rear surface of the substrate.